The cumulative methane production from dairy cattle slurry can be explained by its volatile solid,temperature and length of storage

In order to refine the national estimate of methane emission from stored cattle slurry, it is important to comprehend the basic characteristics of methane production. Two dairy cattle slurries were obtained from livestock farms located in Hokkaido (a northern island) and Kyushu (a southern island). The slurries were diluted with water into three levels: undiluted, three times diluted, and 10 times diluted. Three hundred mL of the slurries were put into a bottle with a headspace volume of 2.0 L, which was filled with nitrogen gas and then sealed by butyl rubber. Four levels of temperature were used for incubation: 35, 25, 15 and 5 °C. The time course of the cumulative methane production per volatile solid (VS) was satisfactorily expressed by an asymptotic regression model. The effect of dilution on the methane production per VS was not distinctive, but that of temperature was of primary importance. In particular, higher temperature yields a higher potential production and a shorter time when the cumulative production reaches half of the potential production. The inclusive and simple models obtained in this study indicate that the cumulative methane production from stored cattle slurry can be explained by VS, temperature and length of storage.     

Approachability and contact behavior of commercial dairy calves to humans

Calves (n = 106) on four dairy farms were observed for their approachability to humans. All calves experienced similar rearing conditions: Beginning individual pen, after birth until weaning at about 2 months, where they were housed individually and fed milk and a milk replacement; Late individual pen, after weaning until grouping at about 3.5 months, where they were housed individually and fed hay, silage and concentrate feed; Beginning group pen, after grouping until 5 months, where they were housed in groups of 2–5 animals and fed hay, silage and concentrate feed; later group pen, from 5 to 7 months. The number of calves that contacted an experimenter who stood in front of their pens for 10 min was recorded on 6 separate days over 3 months. Latency to touch and time spent in activities during touching such as sucking, licking, biting and rubbing were also measured. There were no significant differences in the latency to touch and the ratio of touch to non‐touch calves between the rearing conditions and the farms. The time spent touching was significantly affected by the interaction between the rearing condition and the farm (P < 0.01). In detail, the time spent sucking (P < 0.001) and licking (P < 0.01) was different between the rearing condition × farm variables. The proportion of calves that approached and touched the experimenter tended to be higher in the farms in which a stockperson worked longer inside and outside their pens (both ρ = 0.95, P = 0.051). These results were interpreted according to the perspectives of early positive reinforcement with food and the habituation process to humans existing nearby.     

Cloning and expression of a pili gene of Corynebacterium renale in Escherichia coli

A plasmid gene library of Corynebacterium renale piliated strain No. 109P+ was prepared in Escherichia coli in order to study the chemical structure of the pili of C. renale. Of 3,000 recombinant clones tested, 5 reacted with anti-pili anti-serum. The gene products of these clones reacted with anti-pili monoclonal antibodies 8/4, 5/2 and B20/3 but lacked the reactivity with 13/4. SDS-PAGE analysis revealed that the expressed protein had a molecular mass of 48 kilodalton and deletion analysis showed that the encoding region for this protein was localized within a 1.4 kilobase gene including a promoter sequence. Immunoelectron microscopy showed that mouse antibodies raised to the expressed protein bound to the entire surface of the pili of C. renale. These results indicate that the cloned gene encodes a major structural protein of C. renale pili.     

Clinicopathological features of canine neuroaxonal dystrophy and cerebellar cortical abiotrophy in Papillon and Papillon-related dogs

Neuroaxonal dystrophy (NAD) was examined in two Papillon dogs and a mix breed dog between Papillon and Chihuahua. In addition, cerebellar cortical abiotrophy (CCA) in a Papillon dog, which had similar clinical and magnetic resonance imaging (MRI) features to those of NAD, was also investigated. The common clinical symptoms of all dogs affected with NAD and CCA, were pelvic limb ataxia and cerebellar ataxia including intention tremor, head tremor, and hypermetria in the early onset. These clinical signs were progressed rapidly, and two dogs with NAD were euthanized by owner's request and the other two died by aspiration pneumonia. MRI examinations and gross observations at necropsy revealed moderate to severe cerebellar atrophy in all cases of NAD and CCA. The most typical histological change of NAD was severe axonal degeneration with marked spheroid-formation in the dorsal horn of the spinal cords, the nuclei gracilis, cuneatus, olivalis and its circumference in the medulla oblongata. The spheroids were characterized as large eosinophilic or granular globes within the enlarged myelin sheaths, sometimes accompanied by moderate accumulation of microglias and/or macrophages. In contrast, such spheroid formation was minimal in the brain of CCA. In the cerebellum, mild to moderate loss of the Purkinje and granular cells were recognized in three dogs with NAD, whereas these changes were more prominent in a dog with CCA. Although the clinical signs and MRI findings relatively resembled between NAD and CCA, the histopathological features considered to be quite differ, suggesting distinct pathogenesis and etiology. Since both NAD and CCA are proposed as the autosomal recessive hereditary disorders, careful considerations might be needed for the breeding of Papillon and Chihuahua dogs.     

Sugar transporter (MfsX) of the major facilitator superfamily is required for flagella-mediated pathogenesis in <Emphasis Type="Italic">Dickeya dadantii</Emphasis> 3937

Dickeya dadantii (syn. Erwinia chrysanthemi) is a causal agent of soft-rot diseases on many crops. Here, we characterized a gene belonging to the major facilitator superfamily (MFS), which is involved in the symport, antiport, or uniport of various substrates, and the survival and virulence of many Gram-negative bacterial animal pathogens, for the possible involvement in the plant pathogenicity of D. dadantii. A marker-exchange mutant of this gene (mfsX) was constructed that had decreased maceration ability in Chinese cabbage, potato, and chicory. Observation with electron microscopy showed greatly reduced numbers of flagella per cell. This mutant had a significant reduction in swimming and swarming motility and a severe reduction in formation of biofilm. Because these phenotypes have been shown to be involved in plant pathogenicity of D. dadantii, mfsX seems to play an important role in pathogenesis of D. dadantii 3937 by its involvement in the expression of these pathogenicity-related phenotypes.     

Cerebroside elicitor confers resistance to fusarium disease in various plant species

ABSTRACT In the rice blast fungus pathosystem, cerebroside, a compound categorized as a sphingolipid, was found in our previous study to be a non-racespecific elicitor, which elicits defense responses in rice. Here we describe that cerebroside C is produced in diverse strains of Fusarium oxysporum, a common soilborne agent of wilt disease affecting a wide range of plant species. In addition, some type of cerebroside elicitor involving cerebroside A, B, or C was detected in other soilborne phytopathogens, such as Pythium and Botrytis. Treatment of lettuce (Lactuca sativa), tomato (Lycopersicon esculentum), melon (Cucumis melo), and sweet potato (Ipomoea batatas) with cerebroside B resulted in resistance to infection by each pathogenic strain of F. oxysporum. Induction of pathogenesis-related genes and H(2)O(2) production by treatment with cerebroside B were observed in tomato root tissues. The cerebroside elicitor showed no antifungal activity against F. oxysporum in vitro, indicating that the cerebroside elicitor activates defense mechanisms to confer resistance to Fusarium disease. These results suggest that cerebroside functions as a non-race-specific elicitor in a wide range of plant-phytopathogenic fungus interactions. Additionally, cerebroside elicitor serves as a potential biologically derived control agent.     

d -Alanine-d -alanine ligase gene ( ddl ) of Erwinia chrysanthemi strain EC16 II: analysis of pectate lyase regulation using ddl ? mutant

 Erwinia chrysanthemi (Ech) triggers soft rot disease mainly by secreting pectate lyase (Pel), which is regulated in a complex manner by many regulatory genes. In a previous study, we used a gene dosage method to show that the ddl gene, which encodes d-alanine-D-alanine ligase, reduced Pel production and tissue maceration by Ech strain EC16n. In this study, the ddl ⁻ marker-exchanged mutant was shown to overcome the long growth lag caused by various salts in the growth medium and to increase Pel production over that by EC16n, especially in a medium containing magnesium salts. Thus, ddl seems to regulate Pel production in a negative manner. Because the profiles of a gel shift assay using the pelE promoter region as the target DNA with crude extracts of EC16n and ddl ⁻ mutant were distinguishable, Ddl is thought to affect the binding of other regulatory proteins. Expression of the ddl gene was induced in the medium containing a low-molecular-weight fraction of potato extract, but it was reduced in that containing both polygalacturonic acid (PGA) and the fraction. The repression of ddl expression by PGA should contribute in part to the in planta hyperinduction of Pel. Received: May 15, 2002 / Accepted: June 20, 2002     

Evolutionary plasticity of monooxygenase-mediated resistance

The cytochrome P450 monooxygenases are an important metabolic system involved in the detoxification of xenobiotics, and are thus one of the major mechanisms by which insects evolve insecticide resistance. However, comparatively little is known about the evolutionary constraints of this insecticide resistance mechanism. We investigated the genetic basis of resistance in a strain of house fly (NG98) from Georgia, USA that had evolved 3700-fold resistance to the pyrethroid insecticide permethrin, and compared this to other permethrin resistant strains of house flies from the US and Japan. Resistance in NG98 was due to kdr on autosome 3 and monooxygenase-mediated resistance on autosomes 1, 2, and 5. These results indicate that the genes which evolve to produce monooxygenase-mediated resistance to permethrin are different between different populations, and that the P450 monooxygenases have some degree of plasticity in response to selection. Monooxygenase-mediated resistance appears to evolve using different P450s, and possibly different regulatory signals controlling P450 expression, even in strains selected with the same insecticide.     

The effect of bark decortication for hiwada production on xylem and phloem formation in Chamaecyparis obtusa

Of all plant materials used to cover the roofs of traditional Japanese buildings, Japanese cypress (Chamaecyparis obtusa) bark, hiwada, has the longest service life and has been used from ancient times. However, wood and bark properties after hiwada harvest have not been evaluated in detail. We studied whether decortication for hiwada production in winter affected xylem and phloem formation. Decorticated trees still preserved all inner bark and part of the outer bark, and both decorticated and control trees had similar annual ring structures at all stem heights in the xylem and phloem. In both xylem and inner bark, no significant difference in ring width at any stem height was found between annual rings before and after decortication. Thus, this study revealed that the decortication of bark for hiwada production does not affect the formation of xylem and the inner and outer bark if decortication is carried out by highly skilled workers in winter.     

杨树不同无性系叶面积模型的选择及其建立

应用Ｌｉ－３０００Ａ叶面积仪测定了８个无性系的叶型及叶面积指标，选择了８个模型，以叶片主脉长（Ｌ）和最大宽（Ｗ），以及两者乘积（Ｌ×Ｗ）为三个变量作与叶面积的相关关系分析，筛选出复相关系数均达０．９５以上的最佳模型为：（１）与两者乘积的叶面积模型：ｌｇＹ＝ａ＋ｂｘ＋ｂ＋ｃｌｇｘ，（２）与最大宽度的模型：Ｙ＝ａ＋ｂｘ＋ｃｘ２。但与叶片主脉长模拟效果较差。此外，还得出了杨树无性系的叶面积通用模型，即：Ｙ＝—０．４５０８２６十０．０００７１Ｘ＋０．９７６３３５ｌｇｘ（ｘ为Ｌ×Ｗ），和Ｙ＝—１．６９７３８７十０．７３３４９７ｘ—０．００１２５３ｘ２（ｘ为Ｗ）。上述８个无性系及杨树通用的模型的建立为叶面积的计算、预测等生理生态研究提供了科学依据，使得叶面积测定更加省时、可靠和方便。